6
x^2 + 6x since 4x + 2x = 6x
Answer:
a) 0.2416
b) 0.4172
c) 0.0253
Step-by-step explanation:
Since the result of the test should be independent of the time , then the that the test number of times that test proves correct is independent of the days the river is correct .
denoting event a A=the test proves correct and B=the river is polluted
a) the test indicates pollution when
- the river is polluted and the test is correct
- the river is not polluted and the test fails
then
P(test indicates pollution)= P(A)*P(B)+ (1-P(A))*(1-P(B)) = 0.12*0.84+0.88*0.16 = 0.2416
b) according to Bayes
P(A∩B)= P(A/B)*P(B) → P(A/B)=P(A∩B)/P(B)
then
P(pollution exists/test indicates pollution)=P(A∩B)/P(B) = 0.84*0.12 / 0.2416 = 0.4172
c) since
P(test indicates no pollution)= P(A)*(1-P(B))+ (1-P(A))*P(B) = 0.84*0.88+ 0.16*0.12 = 0.7584
the rate of false positives is
P(river is polluted/test indicates no pollution) = 0.12*0.16 / 0.7584 = 0.0253
Answer:
x=3
Step-by-step explanation:
Given,
1 = 1/(x-2)
Multiply both sides by (x-2),
1*(x-2) = 1/(x-2) * (x-2)
x-2 = 1
Adding 2 on both sides,
x-2+2 = 1+2
x = 3
You want to find the time (x) when the distance from desitnation is 0:
d = 0,
d(x) = 1375 - 110x
0 = 1375 - 110x
110x = 1375
x = 1375/110
<u>x = 12.5 hrs</u>
We know that
<span>1 1/8 gallons----------> (1*8+1)/8-------> 9/8 gallons
</span><span>13 1/2 miles----------> (13*2+1)/2-------> 27/2 miles
if 9/8 gallons-------------------> 27/2 miles
1 gallons----------------------> X
X=(27/2)/(9/8)---------> 216/18--------> 12 miles
the answer is 12 miles</span>
